Preparation, structural characterization, and bioactivities of polysaccharides from Psidium guajava: A review

Caseinate-coated zein nanoparticles as potential delivery vehicles for guavinoside B from guava: Molecular interactions and encapsulation properties

Guavinoside B (GUB) is a characteristic constituent from guava with strong antioxidant activity; however, its low water solubility limits its utilization. Herein, we investigated the interaction between GUB and zein, a prolamin with self-assembling property, using multiple spectroscopic methods and fabricated GUB-zein-NaCas nanoparticles (GUB-Z-N NPs) via the antisolvent coprecipitation approach. GUB caused fluorescence quenching to zein via the static quenching mechanism. Fourier-transform infrared spectroscopy and computational analysis revealed that GUB bound to zein via van der Waals interaction, hydrogen bond, and hydrophobic forces. The GUB-Z-N NPs were in the nanometric size range (< 200 nm) and exhibited promising encapsulation efficiency and redispersibility after freeze-drying. These particles remained stable for up to 31 days at 4 °C and great resistance to salt and pH variation, and displayed superior antioxidant activity to native GUB. The current study highlights the potential of zein-based nanoparticles as delivery vehicles for GUB in the food industry.

Application of ionic liquid ultrasound-assisted extraction (IL-UAE) of lycopene from guava (Psidium guajava L.) by response surface methodology and artificial neural network-genetic algorithm

Lycopene-rich guava (Psidium guajava L.) exhibits significant economic potential as a functional food ingredient, making it highly valuable for the pharmaceutical and agro-food industries. However, there is a need to enhance the extraction methods of lycopene to fully exploit its beneficial uses. In this study, we evaluated various ionic liquids to identify the most effective one for extracting lycopene from guava. Among thirteen ionic liquids with varying carbon chains or anions, 1-butyl-3-methylimidazolium chloride demonstrated the highest productivity. Subsequently, a single-factor experiment was employed to test the impact of several parameters on the efficiency of lycopene extraction using this selected ionic liquid. These parameters included extraction time, ultrasonic power, liquid-solid ratio, concentration of the ionic liquid, as well as material particle size. Moreover, models of artificial neural networks using genetic algorithms (ANN-GA) and response surface methodology (RSM) were employed to comprehensively assess the first four key parameters. The optimized conditions for ionic liquid ultrasound-assisted extraction (IL-UAE) were determined as follows: 33 min of extraction time, 225 W of ultrasonic power, 22 mL/g of liquid-solid ratio, 3.0 mol/L of IL concentration, and extraction cycles of three. Under these conditions, lycopene production reached an impressive yield of 9.35 ± 0.36 mg/g while offering advantages such as high efficiency, time savings, preservation benefits, and most importantly environmental friendliness.

Recent trends in extraction, purification, structural characterization, and biological activities evaluation of Perilla frutescens (L.) Britton polysaccharide

Perilla frutescens (L.) Britton is an annual herb plant of the Perilla genus in the Labiatae family, which is commonly utilized as an edible and medicinal resource. Polysaccharides are among the major components and essential bioactive compounds of P. frutescens, which exhibit a multitude of biological activities, including antioxidant, antitumor, anti-fatigue, immunoregulation, hepatoprotective, anti-inflammatory, and lipid-lowering effects. As a natural carbohydrate, P. frutescens polysaccharide has the potential to be utilized in the development of drugs and functional materials. In this paper, we provide an overview of progress made on the extraction, purification, structural characterization, and bioactivity of polysaccharides from different parts of P. frutescens. The challenges and opportunities for research are discussed, along with the potential development prospects and future areas of focus in the study of P. frutescens polysaccharides.

Molecular Detection of Secreted Aspartyl Proteinases (Saps) From Dental Isolates of Candida albicans and Targeting With Psidium guajava Biocompounds: An In Vitro and In Silico Analysis

Introduction Candida albicans (C. albicans) is an opportunistic yeast-like fungus and is considered a functional biome of the oral and gut microbiomes. The sap gene and its types play a vital role in the pathogenesis of C. albicans. The emergence of resistance traits is a major problem, and targeting the same with alternative medicines has sparked renewed interest in recent years. Objectives This study is thus aimed at detecting the frequency of sap gene types in the clinical isolates of C. albicans and evaluating the antifungal effect of the crude methanolic extract of Psidium guajava (P. guajava). Further in silico assessments will assess the inhibitory effect of six compounds of P. guajava against the Sap protein. Materials and methods C. albicans was characterized phenotypically in 20 patients with root caries, and the sap gene was detected by PCR. The crude methanolic extract was prepared, and its antifungal efficacy was evaluated by the agar well diffusion method. Auto-docking was performed to assess the best compound based on the docking and overall interactions. Results Six isolates were identified as C. albicans and sap gene types 1-3 were detected in the four strains. P. guajava methanolic extracts showed a promising antifungal effect at varying concentrations. In silico analysis showed myricetin possessing the maximum number of hydrogen bonds and high docking energy with one violation. Conclusion The study concludes that P. guajava has a promising inhibitory effect against C. albicans with myricetin as the best compound to target the sap gene of C. albicans. However, further experimental studies are to be considered for its effectiveness in treating the infections caused by C. albicans.

Optimization of Extraction Process, Preliminary Characterization and Safety Study of Crude Polysaccharides from Morindae Officinalis Radix

In this study, the hot water extraction process of crude polysaccharides from Morindae officinalis radix (cMORP) was conducted and optimized through a single-factor test and orthogonal experimental design. With the optimal extraction process (extraction temperature of 80 °C, extraction time of 2 h, liquid/solid ratio of 15 mL/g, and number of extraction of 1), the cMORP was obtained by the ethanol precipitation method. The chemical properties and preliminary characterization of the cMORP were analyzed by chemical or instrumental methods. Furthermore, to indicate a preliminary study on safety, a single oral dose of 5000 mg/kg body weight (BW) was administered orally to Kunming (KM) mice for acute toxicity, and the cMORP was administered orally to KM mice once a day at doses of 25, 50, and 100 mg/kg BW for 30 days. General behaviors, body weight variations, histopathology, relative organ weights, and hematological and serum biochemical parameters were observed and recorded. The results suggested there were no toxicologically significant changes. Based on the safety study, cMORP can be initially considered non-toxic with no acute oral toxicity up to 5000 mg/kg BW and safe at up to 100 mg/kg BW in KM mice for 30 days.